The move could put the UK at odds with US President Donald Trump as the video platform is at the centre of a row in the US over alleged links to the Chinese state and Mr Trump is threatening to ban the app.
But reports suggest the UK is set to give the green light to a new headquarters for the service in London, with key executives relocating to the UK as part of the move.
TikTok declined to comment on its plans.
Last month, the app’s head of public policy for Europe, Theo Bertram, denied the company had halted plans for a London HQ because of escalating tensions between the UK and China over Huawei and Hong Kong.
“We are still thinking about what to do about our global HQ and we haven’t made any decision on that yet, and anything else is speculation,” he said.
TikTok has come under scrutiny over US fears that personal data could be accessed by China, something the app has repeatedly denied.
Meanwhile, Microsoft has confirmed it is in talks to buy the platform in the US after discussions between its chief executive Satya Nadella and President Trump over the app’s security.
US Secretary of State Mike Pompeo said on Sunday the White House plans to take action against a number of Chinese software companies it sees as linked to the Chinese Communist Party.
“These Chinese software companies doing business in the United States, whether it’s TikTok or WeChat — there are countless more … are feeding data directly to the Chinese Communist Party, their national security apparatus,” he said.
TikTok, which is owned by Chinese firm Bytedance, insists personal data cannot be accessed by Beijing and that it has no ties to the Communist Party.
Microsoft said its discussions with Bytedance over a possible buyout would be completed by September 15.
“Following a conversation between Microsoft CEO Satya Nadella and President Donald J. Trump, Microsoft is prepared to continue discussions to explore a purchase of TikTok in the United States,” the US tech giant said.
“Microsoft fully appreciates the importance of addressing the president’s concerns. It is committed to acquiring TikTok subject to a complete security review and providing proper economic benefits to the United States, including the United States Treasury.”
